Andriy H. Nevidomskyy

Chemically active substitutional nitrogen impurity in carbon nanotubes.

We investigate the nitrogen substitutional impurity in semiconducting zigzag and metallic armchair single-wall carbon nanotubes using ab initio density functional theory. At low concentrations (less than 1 at. %), the defect state in a semiconducting tube becomes spatially localized and develops a flat energy level in the band gap. Such a localized state makes the impurity site chemically and electronically active. We find that if two neighboring tubes have their impurities facing one another, an intertube covalent bond forms. This finding opens an intriguing possibility for tunnel junctions, as well as the functionalization of suitably doped carbon nanotubes by selectively forming chemical bonds with ligands at the impurity site. If the intertube bond density is high enough, a highly packed bundle of interlinked single-wall nanotubes can form.

The role of the interlayer state in the electronic structure of superconducting graphite intercalated compounds

Although not an intrinsic superconductor, it has been long--known that, when intercalated with certain dopants, graphite is capable of exhibiting superconductivity. Of the family of graphite--based materials which are known to superconduct, perhaps the most well--studied are the alkali metal--graphite intercalation compounds (GIC) and, of these, the most easily fabricated is the C

Quantum Criticality Without Tuning in the Mixed Valence Compound β-YbAlB4

{}_8

Nematic spin correlations in the tetragonal state of uniaxial-strained BaFe2−xNixAs2

K system which exhibits a transition temperature

High-pressure phase and transition phenomena in ammonia borane NH3 BH3 from x-ray diffraction, Landau theory, and ab initio calculations

\bm{T_c\simeq 0.14}

Frustration and the Kondo Effect in Heavy Fermion Materials

K. By increasing the alkali metal concentration (through high pressure fabrication techniques), the transition temperature has been shown to increase to as much as

Layered Kondo lattice model for quantum critical beta-YbAlB4.

\bm 5

In Situ Diffraction Study of Catalytic Hydrogenation of VO2: Stable Phases and Origins of Metallicity

K in C

Avoided Quantum Criticality and Magnetoelastic Coupling in BaFe2-xNixAs2

{}_2

β-YbAlB4: A Critical Nodal Metal

Na. Lately, in an important recent development, Weller \emph{et al.} have shown that, at ambient conditions, the intercalated compounds \cyb and \cca exhibit superconductivity with transition temperatures